net: add change_carrier netdev op

This allows a driver to register change_carrier callback which will be
called whenever user will like to change carrier state. This is useful
for devices like dummy, gre, team and so on.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Acked-by: Flavio Leitner <fbl@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 19 insertions, 0 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 515473ee52cb..21c5b976dcf3 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5027,6 +5027,25 @@ int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa)
 }
 EXPORT_SYMBOL(dev_set_mac_address);
 
+/**
+ *      dev_change_carrier - Change device carrier
+ *      @dev: device
+ *      @new_carries: new value
+ *
+ *      Change device carrier
+ */
+int dev_change_carrier(struct net_device *dev, bool new_carrier)
+{
+        const struct net_device_ops *ops = dev->netdev_ops;
+
+        if (!ops->ndo_change_carrier)
+                return -EOPNOTSUPP;
+        if (!netif_device_present(dev))
+                return -ENODEV;
+        return ops->ndo_change_carrier(dev, new_carrier);
+}
+EXPORT_SYMBOL(dev_change_carrier);
+
 /*
  *      Perform the SIOCxIFxxx calls, inside rcu_read_lock()
  */